New regulations for exhaust gas emissions for motor vehicles continue to provide challenges for emission and onboard diagnostic (OBD)) compliance. Such regulations require that levels of hydrocarbons (HC), carbon monoxide (CO), and nitrogen monoxide (NO) in exhaust gas exiting an exhaust system of a motor vehicle be below predefined levels set by one or more government agencies and regulations, e.g. the Clean Air Act. There is also a desire to reduce fuel consumption by motor vehicles. Accordingly, a need exists for improved combustion control strategies, systems and methods.